JPS6245077B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a color-forming recording material characterized in that a novel dipyrrolidinyl diphenylmethane derivative represented by the general formula () is used as a color-forming reactive colorless substance (hereinafter referred to as a color-forming agent). [In the formula, Donating substances are known, and these include activated clay materials such as acid clay, attapulgite clay, silton clay, bentonite, kaolin, etc. or acidic organic polymers such as phenol-formalin polymers, phenolacetylene polymers, salicylic formalin polymers. It is also known that it develops color when it comes into contact with electron-accepting substances such as bisphenol A and bisphenol A. Among these, phenothiazine compounds are mainly used as slow color formers, and one of them, benzoylleucomethylene blue, is mixed with crystal violet lactone, a phthalide compound that has a deep blue-purple color as an initial image. This overcomes the instability of crystal violet lactone against sunlight and moisture. However, the color tone of this image tends to be greenish compared to the clear blue-purple of crystal violet lactone, and the contrast of the color tone is poor, and the initial color density of crystal violet lactone tends to decrease, especially in acidic organic polymers. When used for pressure-sensitive copying paper, organic solvents such as chlorinated biphenyl, alkylated biphenyl, etc.
When dissolved in alkylated naphthalene, kerosene, n-octyl phthalate, etc., there are many aspects in which it is not effective, such as coloring from greenish to blue. Known diphenylmethane compounds having a structure similar to that of the present invention, such as 4,4'-bisdialkylaminodiphenylmethane, gradually develop a blue-blue-green color when contacted with activated clay materials or acidic organic polymers. It has not yet been put into practical use because the stability of the colored image under sunlight is very poor and the sublimability is extremely high. In order to overcome the drawbacks of the conventionally used benzoylleucomethylene blue or the known diphenylmethane, the present inventors conducted detailed research on bisdiaminodiphenylmethane compounds, and found that that the dipyrrolidinyl diphenylmethane derivative formed in the active clay material and the acidic organic polymer rapidly develops color;
The density of the developed color image is high and the stability to sunlight is very good; the color density of the initial image does not decrease even when mixed with other color formers, such as phthalide compounds and fluoran compounds; It was discovered that the sublimation property was significantly lower than that of diphenylmethane. More specifically, other coloring agents that can be used in combination with the dipyrrolidinyl diphenylmethane derivative represented by the general formula () of the present invention include crystal violet lactone, benzoylleucomethylene blue, and disubstituted fluoran. Compound,
For example those described in British Patent No. 1182743 or British Patent Application No. 24079/73 and Belgian Patent No. 815291 and No. 815294 or 3,7 bisindolyl phthalide, e.g. Examples include those described in Specification No. 2259711. 3,7-bisdimethylamino-10-benzoylphenothiazine (A), known 4,4'-bisdimethyldiaminodiphenylmethane (B), used as a slow color forming agent to demonstrate the characteristics of the present invention. ,4,4'-
Bisdiethyldiaminodiphenylmethane (C), crystal violet lactone (D) used to form a blue-violet initial image, and dipyrrolidinyldiphenylmethane represented by the general formula () of the present invention 4,4'-bispyrrolidinyldiphenylmethane (E) and 4,4'-bispyrrolidinyl-2,2'-dimethoxydiphenylmethane (F), which are one of the derivatives.
The results of a comparative test were as follows. 1 Comparison of sublimation properties (B), (C), (E), (F) 25μ of each 3.3% toluene solution
was dripped onto Toyo Paper No. 2 and the toluene was thoroughly dried and evaporated, then paper coated with acidic clay (hereinafter referred to as clay paper) was layered tightly and heated for 100 minutes under a load of 2 kg.
Keep at ℃ for 1 hour. The colored image obtained on the clay paper was then exposed to sunlight for 30 minutes, and the color density was measured using a Macbeth reflection densitometer. #106 filter was used.

[Table] As mentioned above, the color development on clay paper by sublimation of (E) and (F) in the present invention is compared to the known (B) and (C).
It was less than 1/10, indicating that the sublimability was significantly improved. When (E) and (F) are used as pressure-sensitive copying papers, sublimation from the microcapsule-coated paper will stain the paper coated with electron-accepting substances such as activated clay materials or acidic organic polymers. This confirms that there is very little fear. 2 Comparison of color development and light resistance A. Each of (A), (B), (C), (E) and (F) was made into a 3% solution of KMC-113 (Kureha Chemical), and this was added at a ratio of 1 mg/m ² on clay paper, and the density of the colored image was reduced to 10
Measurements were made after 1 minute, 1 hour, 12 hours, 24 hours, and 72 hours, and then the color image was irradiated with sunlight for 30 minutes, 1 hour, and 2 hours, and the density of the color image was measured. Measurement of reflection density is 1
It was done in the same way as.

[Table] B (D) and (D): (A) 1:1 mixture, (D): (E) 1:1 mixture, (D): (F) 1:1 mixture, each in the same manner as in A. A comparison was made based on the method.

[Table] C A 3% solution of each of (A), (B), (C) and (E) KMC-113 (Kureha Chemical) was prepared on paper coated with phenol-formalin polymer at a rate of 1 mg/ ^m2 . (hereinafter referred to as resin paper), and the color development and light fastness of the images were compared using the same method as in A.

[Table] (D), (D):(A) 1:1 mixture, and (D):(E) 1:1 mixture were compared in the same manner as C.

[Table] As is clear from the results of the above comparative test, (E) and (F) in the present invention are conventionally used (A) and known (B) in color development on clay paper and resin paper. , compared to (C), it shows superior color development and high stability against sunlight, indicating that it has high utility value as a color-forming recording material for use alone or in combination with other color-forming agents. Recognize. To use the dipyrrolidinyl diphenylmethane derivative represented by the general formula () in pressure-sensitive copying paper, for example, the method described in U.S. Pat. No. 2,800,458 or U.S. Pat. No. 2,806,457 can be used. You can do it by folding it. The dipyrrolidinyl diphenylmethane derivative represented by the general formula () of the present invention can be prepared by adding 2 moles of pyrrolidinylbenzene or substituted pyrrolidinylbenzene () and 1 mole of formaldehyde to water or an alcoholic solvent such as hydrochloric acid, sulfuric acid, etc. 4,4′- It is easily synthesized by obtaining bisdiamino-substituted diphenylmethane () and then reacting it with 2 moles of 1,4 dipromptan in water or an alcohol solvent in the presence of an alkali such as sodium carbonate, sodium bicarbonate, or sodium hydroxide.

【formula】

【formula】

Dipyrrolidinyldialkoxydiphenylmethane can also be obtained by reacting 1 mole of dipyrrolidinyldihydroxydiphenylmethane with 2 moles of dialkyl sulfuric acid in the presence of an alkali such as sodium hydroxide. The properties of several examples of the dipyrrolidinyl diphenylmethane derivatives of the present invention having the same characteristics as those in (E) and (F) above will be shown below, and the present invention will be explained more specifically by the synthesis method and examples. As will be clear, the present invention is not limited to the following synthetic methods and examples.

[Table] Synthesis example 1 Add 29.4 g of pyrrolidinium benzene to 10 ml of water, 9 g of 37% formaldehyde, and 0.8 g of formic acid, and react at 40-45°C for 5 hours. The resulting precipitate was separated, washed with water, and then recrystallized with methanol to obtain 15.5 g of 4,4'-bispyrrolidinyldiphenylmethane as colorless crystals with a melting point of 105-106°C. Synthesis example 2 31g of m-pyrrolidinium toluene in methanol
Add to 70ml 37% formaldehyde 9g and 35% hydrochloric acid 10ml and react at room temperature for 10 hours, then add 15g sodium acetate and 30ml methanol. Separate the precipitate, wash with water, and recrystallize with methanol to obtain a melting point of 131-133.
20.0 g of 4,4'-bispyrrolidinyl-2,2'-dimethyldiphenylmethane was obtained as colorless crystals at . Synthesis example 3 35 g of m-pyrrolidinium chlorobenzene was reacted in the same manner as in Synthesis Example 1, and the resulting precipitate was recrystallized from methanol to give 4,4'-bispyrrolidinyl-2, 17.5 g of 2'-dichlorodiphenylmethane was obtained. Synthesis example 4 35.4 g of m-pyrrolidinium anisole was reacted in the same manner as in Synthesis Example 1, and the resulting precipitate was recrystallized from toluene to give 4,4'-bispyrrolidinyl-2, 20.0 g of 2'-dimethoxydiphenylmethane was obtained. Synthesis example 5 32.6 g of m-pyrrolidinium phenol was reacted in the same manner as in Synthesis Example 2, and the resulting precipitate was separated, washed with water, and recrystallized with toluene to give a melting point of 176-178.
4,4'-bispyrrolidinyl-2,2'-dihydroxyldiphenylmethane as colorless crystals at °C
Obtained 20.0g. Synthesis example 6 4,4′-bispyrrolidinyl-2 of Synthesis Example 5,
Dissolve 8 g of 2'-dihydroxyldiphenylmethane in 100 ml of 5% aqueous sodium hydroxide solution, add 10 g of diethyl sulfate at 70-80°C, and react for 1 hour. Separate the precipitate, wash with water, and recrystallize with toluene to obtain a melting point of 111.
5 g of 4,4'-bispyrrolidinyl-2,2'-diethoxydiphenylmethane as colorless crystals at -113°C
I got it. Example 1 4,4'-bispyrrolidinyl-2 of Synthesis Example 4,
3 parts of 2'-dimethoxydiphenylmethane to KMC-
113 (Kureha Chemical) and emulsified by adding a solution of 20 parts of gum arabic and 160 parts of water to this solution.
A solution of 20 parts of acid-treated gelatin and 160 parts of water is added to this emulsion to proceed with coacervation, and the gelatin is mixed around the oil droplets of the solvent in which the coloring agent is dissolved.
After forming a thick liquid film of gum arabic, PH
4.4, and 3.8 parts of a 37% formaldehyde aqueous solution was added to cure the liquid film. Then, cool to 10°C, add sodium hydroxide solution to adjust pH to 9, and adjust to 5.
- Leave for 6 hours to allow encapsulation to proceed completely. This encapsulation liquid is applied to paper and allowed to dry.
This paper was brought into close contact with paper coated with acid clay as an acidic electron-accepting adsorbent, and when pressure from a ballpoint pen or impact from a typewriter was applied, a blue image was obtained on the surface of the acid clay. This image showed strong sunlight stability. Example 2 3 parts of 4,4'-bispyrrolidinyldiphenylmethane from Synthesis Example 1 was dissolved in 100 parts of KMC-113 (Kureha Chemical), microencapsulated in the same manner as in Example 1, and applied to paper. did. When this was brought into close contact with paper coated with a phenol-formalin polymer as an acidic electron-accepting agent, and pressure from a ballpoint pen or impact from a typewriter was applied, a bluish-purple image was obtained on the surface of the phenol-formalin polymer. This image showed strong sunlight stability. Example 3 1.5 parts of 4,4'-bispyrrolidinyldiphenylmethane from Synthesis Example 1 and 1.5 parts of crystal violet lactone were dissolved in 100 parts of KMC-113 (Kureha Chemical), and color was developed in the same manner as in Example 1. A bluish-purple image was immediately obtained. This image showed strong sunlight stability.

Claims (1)

[Claims] 1. General formula It is characterized by containing a novel dipyrrolidinyl diphenylmethane derivative represented by the formula [wherein X is a hydrogen atom, a chlorine atom, a lower alkyl group, a lower alkoxy group, or a hydroxyl group] as a color-forming reactive colorless substance. Chromogenic recording material.